Pulmonary Arteriovenous Fistulas: In reply

Abstract

We thank Dr Boczko for his interest in our paper. The 4% occurrence of CAVF in our series was lower than that reported in the literature for 2 possible reasons. First, only patients with neurologic symptoms were evaluated with neurologic imaging, and second, we were evaluating all patients with PAVF and not necessarily HHT. Only 52 (56%) of our 93 patients had HHT, and thus, we would expect a lower incidence of CAVF given that the 2 populations of patients are different. The natural history of CAVF in patients with HHT is not known. In fact, Putnam et al1Putnam CM Chaloupka JC Fulbright RK Awad IA White Jr, RI Fayad PB Exceptional multiplicity of cerebral arteriovenous malformations associated with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome).AJNR Am J Neuraradiol. 1996; 17: 1733-1742PubMed Google Scholar state, “Because the natural course of CAVF in HHT is not known, the risk versus benefit of extensive interventions cannot be justified.” The common neurologic manifestations in these patients relate to PAVF and paradoxical embolization. Various types of CNS vascular anomalies also exist in HHT, however, including telangiectasia, cavernous angioma, and arteriovenous malformation.2Kadoya C Momota Y Ikegami Y Urasaki E Wada S Yokota A Central nervous system arteriovenous malformations with hereditary hemorrhagic telangiectasia: report of a family with three cases.Surg Neurol. 1994; 42: 234-239Abstract Full Text PDF PubMed Scopus (38) Google Scholar In patients with HHT, CAVFs are often very small, multiple, and deep-seated.2Kadoya C Momota Y Ikegami Y Urasaki E Wada S Yokota A Central nervous system arteriovenous malformations with hereditary hemorrhagic telangiectasia: report of a family with three cases.Surg Neurol. 1994; 42: 234-239Abstract Full Text PDF PubMed Scopus (38) Google Scholar The overall hemorrhagic risk in non-HHT patients with CAVF is approximately 3% annually.3Wagner BJ Richardson KJ Moran AM Carrier DA Intracranial vascular malformations.Semin Ultrasound CT MRI. 1995; 16: 253-268Abstract Full Text PDF PubMed Scopus (9) Google Scholar This has not been studied in HHT patients. We agree with Dr Boczko about the importance of screening patients with HHT. More studies need to be performed to identify the natural history of CAVF specifically in patients with HHT. Data also need to be collected on the age at which to start screening, which screening tests are optimal, whether to perform magnetic resonance imaging on asymptomatic family members of HHT patients, and when to perform cerebral angiography. Screening patients with HHT and their family members for multisystem AVFs is recommended. The details of how best to screen and with what modalities require further study. Pulmonary Arteriovenous FistulasMayo Clinic ProceedingsVol. 74Issue 12PreviewTo the Editor. The 15-year experience with pulmonary arteriovenous fistulas (PAVFs) at the Mayo Clinic1 interested me as a neurologist because I investigated a family with hereditary hemorrhagic telangiectasia (HHT) in the mid 1960s and reviewed the then-existing literature.2 The mother and younger daughter both proved to have coexistent PAVF and cerebral arteriovenous malformation (CAVM).3 These are among the first authenticated cases reported. Only 2 patients with HHT with symptomatic gross central nervous system (CNS) vascular malformation were described in the literature to that date. Full-Text PDF